Thread-controlling device for sewing-machines.



F. ZALESKL THREAD commouma ogvics FOR 3 m MACHWES.

APPLlCATiOH FILED FEB. #0; i915.

m m m m a w Vem K WITNESSES.-

STATES @FFlQE FBIAH K ZALESKI, 02F SOMERVILLE, MASSAGHU SETTS, ASSIGNOB TO THE REECE BUTTON HOLE MACHINE COMPANYj- OF BOSTON, MASSACHUSETTS, A CORPORATION OF MAINE.

Specification of Letters Patent.

THREAD-CONTROLLING DEVICE FOR SEWING-MACHINES.

Patented Dec. '7, 1915.

Application filed February 10, 1915. Seriil No. 7,422.

To aZZ whom it may concern:

iie it known that I, FRANK ZALESKI, a subof the Emperor of Germany, residing Somcrville, county of Mrddlesex, State of Massachusetts, have invented an Improves ianying drawing, is a specification, like characters on the drawing representing like arts. P This invention relates to sewing machines and particularly to buttonhole sewing machines and the object of the invention is to provide a novel device for drawing oil a length of needle thread from the tension device in the interval between the stitching operations on two successive buttonholes so that when the stitching operation is begun on any buttonhole there will be a sufficient slack in the needle thread on the delivery side ofthe tension to permit the first stitch to be properly. formed and to obviate the danger that in forming the first stitch the end of the needle thread will be drawn through-the material and thus fail to lnterlock with the under thread.

The invention herein shown is particularly applicable to buttonhole sewing machines of that type wherein the stitch-forming instrumentalities have a turning movement about a vertical axis during the operation of stitching the buttonhole to permit the buttonhole stitches to be formedaround the ends of the buttonhole, and in which the rotary movement of the needle is made use of to draw the required length of needle thread through the tension device after the stitching operation has ceased.

While my invention is applicable to varineedle has a rotary movement, I have chosen herein to illustrate it as it would be applied to a buttonhole sewing machine of the wellknown lteece type, examples of which are to he found in the following United States patents: No. 494,280, March 28, 1893; No. M38316, May 23, 1893; No. 655,637, August 7, 1900; No. (380,192, August 6, 1901. These sewing machines illustrated in said patents comprise a clamp frame in which the work is clamped and a so-called stitch frame carrying upper and under thread mechanism, the upper thread mechanism being in the form oi? a straight eye-pointed needle carried bya vertically-reciprocating needle bar. The clamp frame and stitch frame are mounted for movement relative to each other to bring the work from the position in which thebuttonhole is cut to that in which the edge stitches are formed on the buttonhole, and the upper thread mechanism comprising the needle bar and also the under thread mechanism are rotatably mounted and means are provided for turning the upper and under thread mechanism at proper points in the cycle of operations to carry the stitching operation around the ends of the buttonhole, such mechanism causing the stitch-forming mechanism to have a reverse or backward turningv movement in the interval between the stitching operations on successive buttonho-les to restore the parts to proper position to begin stitching operations on such second buttonhole.

The present invention involves a threadcontrolling device which is actuated by such reverse turning movement of the upper thread mechanism to draw through the tension device for the upper thread a surplus length of upper thread, which device operates to release or give up instantly this surplus length of thread immediately after it has been drawn through the tension device. As a result, when the stitching operation )11 any buttonhole begins the upper or needle thread presents a certain amount of slackness between the tensio-nand the needle so that when the first stitch is made this slackness furnishes sufiicient thread to form the first stitch without drawing thread through the tension device, thus insuring that the first stitch will be properly formed and obviating the danger that the needle thread will be drawn ba'ckwardly through the eye of the needle during the formation of the first stitch by the tension on the thread.

In order to give an understanding of my invention I have illustrated in the drawings a selected embodiment thereof which will now be described, after which the novel features will be pointed out in the appended claims.

In the drawings, Figure 1 is a side view of a portion of a buttonhole sewing machine such as illustrated in the above-mentioned patents showing my improvements applied thereto; Fig. 2 is a side View of the threadcontrolling device showing the screw-thread- 1 neeoie, her a ruse i needle car in section; Fig. 3 is a perspective view of the thread-controlling device; ligs. d, 5 and 6 are top plan views of the oven hanging arm of the sewing machine showing the thread-controlling device in different positions.

In the sewing machine herein illustrated 1 indicates the clamp frame to which the work is clamped and 2 is a portion of the stitch frame which carries the upper and under thread mechanisms, the former only being herein shown. Such upper thread mechanism in the form of an eye-pointed ne dle 8 sustained by a hollow reciprocatin that is v wically reciprocateo in the head :3 of stitch-ireme as usual in devices of this class 5 indicates generally the work clamp car ried the clamp frame and in which the work is clamped during the stitching operation.

the operation of sewing machines of this type the machine is brought to rest with the parts in the position shown in full. lines Fig. l. lVhen the machine is started the work clamp. 6 is first clamped onto the work and then the stitch frame and work frame have a relative movement to bring the needle into the dotted line position Fig. 1 relative to the work clamp, and when the parts have reached this relative position the stitch-forming mechanism is set in oper'r tion automatically to cause the stitches to be formed around the edge of the buttonhole, and during this operation the upper thread mechanism as well as the under thread mechanism is turned about a vertical axis to cause the stitches to be formed around the ends of the buttonhole. When the stitching has been completed the stitch-forming mechanism is brought to rest and then the stitch frame and clamp frame have another relative movement to restore the parts to the full line positions Fig. l, and during this latter movement the upper and under thread mechanisms are turned backwardly to bring them into their initial position. This turning movement of the upper and under thread mechanism is derived from an oscillatory shaft 7 carrying gear sectors that mesh with pinions on the upper and under thread mechanisms, respectively, the pinion on the upper thread mechanism being shown at 8 and the sector with which it meshes being shown at 9, this being a construction common to the abmementioned patents. The upper thread 10 extends from the source of supply through a suitable tension device 11 of any construction, thence to a take-up l2 and from the take-up it passes to the upper end of the needle bar, 4': and is threaded through the hollow needle bar to the eye-pointed needle. In some sewing niachines of this type, such, for instance, as that illustrated in my co-pending application Se. No. 873,127, filed November 20, 191%, a thread-clamping devlce 120 1s employed in connection Wlth the work clamp 6, said thread-clamping device being so constructed that when thcclamp frame and stitch-frame have their relative movement at the end of the stitching operation to carry the needle from the dotted to the full line position Fig. 1, the needle thread will be drawn into the clamp The purpose of this thread clamp is to hold the end 30*roi' the needle thread while the first stitch is formed on the next succeeding buttonhole so as to insure that said stitch will be properly formed.

ln sewing machines having this construction it is essential that the end of the needle thread should not be pulled outirom the clamping device when the stitching operation is started and theneedle is making its first penetrating thrust, for if this should occur the upper thread will not be properly interlocked with the under thread to form the first stitch, thus making an imperfect buttonhole. lily invention provides a thread-controlling device which operates to draw through the tension device for the upper thread certain. amount of slack thread prior to the beginning of the stitching open ation and while the needle is being moved trom the full to the dotted line position, Fig. 1, so that when the stitching operation is commenced and the needle 3 makes its first penetratii'ig thrust, the thread which is used to make the first needle loop will be relieved from the tension of the tension de. vice 11, thus avoiding the possibility of the thread being pulled out from the clamping device. The device I have herein illustrated for thus pulling off a certain amount of needle thread prior to the beginning of the stitching operation is constructed so that it will act during a portion of the reverse turning movement of the needle bar to draw oil the required amount of needle thread, and when such required amount has been drawn off will instantly release or give up the slack thus leaving the needle thread between the tension 11 and the point of the needle with a certain amount of slack during the remaining turning movement of the needle bar. In the illustrated embodiment of my invention this vdevice is in the form of a disk or plate 13 secured to the upper end of the needle bar 4 and provided with an aperture 18 through which the needle ing provided with a curved thread-engaging portion 19 in the form of a wall or flange rising from the periphery of the disk and provided at oneend with a thread-re oeiving notch 20. This Wall or flange 19 is iornied on its outer side With a thread-receiving groove 21 and the end opposite the notch 20 is tapered or beveled, as at 22, so

thread 10 passes, said disk or plate beshown it as provided'with a screw-threaded stem 23 which screws into the upper end of the needle bar, a lock nut 24 being employed to lock'thedevice in adjusted position. The

manner in which the deviceoperates will be readily seen from Figs. 4, 5 and 6.

The thread-controlling device is so adjusted on the needle bar thatwhen the machine comes to rest the thread-engaging portion 19 will have the position shown in full lines Fig. 4, the needle thread passing from the aperture 18 around the notched end 20 of the portion 19, as shown in said Fig. 4.

When the sewing machine is started in operation the stitch frame and clamp frame have a moment' relative to each other, as above set forth, during which the needle bar is carried from. the full to the dotted line position Fig. 1, and during thisrelative movement the needle bar is turned about its axis in the direction of the arrow a, Fig. 4, through approximately one complete revolution to bring the upper and under thread mechanisms into proper position to begin stitching on the buttonhole. During this time the end of the needle thread 10 is held by the thread-clamping device 120. During the initial rotative movement of the needle 11a certain length of needle thread. When the parts have reachedtheposition shown in Fig. 5 the needle thread 10 is being drawn over the'inclined edge 22 of the flange 19, and as the 'rotationof the disk is continued the tensien (in the thread will pull it 0d or strip it from the flange, thus giving up to the 4a thread the slack which has been placeo needle makes its first penetrating thrust, it

therein." ,The parts continue to rotate until the position shown in Fig. 6 is reached at which time the stitch frame and clamp frame have moved into the relative positions shown by dotted lines Fig. 1 and the stitching operation is about to begin. When the will carry the needle thread through the material toform a needle loop therein and the slack thread which has been given to the needle thread by the device above described is suflicient to provide for the formation of the first needle loop without drawing any thread through the tension device 11. The formation of the needle loop, therefore, is

accomplished without subjecting the thread end held in the-thread-clamping device 120 to the severe strain which would result if the thread to form the needle loop during the first thrust of the needle had to be drawn through the tension device 11. The firstv stitch, therefore, will be formed properly and without any danger that the thread will be pulled out from the thread clamp.

As the stitching operation begins the up per and under thread mechanisms are rotated in the direction. of the arrow Z) in Fig.

4, but this rotative movement does not affect the needle thread 10 in any way because as the' disk 13 rotates the needle thread will simply ride up on the inclined portion 22. During the stitching operation, therefore;

the needle thread will always pass directly needle bar will be turned through approx1- mately a quarter of a revolution to bring the parts in the positiop-llshown in Fig. 4, j

and during such movement a small amount of needle thread 10 will be drawn through the tension device 11. The machine. is brought to rest at this point and when it is set in' operation again the continued turning movement of the needle bar 4 and disk 13 from the position shown in Fig. 4 to that shown in Fig. 5 will draw through the tension device 11 the requiredamount of needle thread to provide for the formation of the first stitch on the next buttonhole, all as above described.

I claim: I

1. In a sewing machine, the combination with upper thread mechanism, of means to rotate it, and means operative during the retation of the upper thread mechanism in one directionboth to draw from the thread supply a length of upper thread, and th n to give up or release said length.

I 2. In a sewing machine, the combination movement a length of upper thread from the int 'with upper thread mechanism, of means to rotate it, and means to draw with a gradual thread supply and then give up said thread instantly during the rotation of the upper thread mechanism in one direction' 3. In a buttonhole sewing machine, the combination with upper thread mechanism, 'of means to rotate it in one direction while stitching around the ends of a buttonhole and in a reverse direction between stitching operations,'and means acting during suchreverse rotative movement thereof both to' draw from the thread supply a length of upper thread and to release or give up said length thereby providing slack thread for the formation of the first stitchof the next buttonhole.

lit-

' combination with a needle bar, of means to rotate it, and means carried by the needle bar and adapted to act on the thread leading thereto during the rotation of the needle bar in one direction both to draw a length of thread from the thread supply and to give up or release said length.

(i. in a buttonhole sewing machine, the combination with a needle bar, of means to rotate it, and a self-stripping pull-off device car 'ied by the needle bar and constructed to acton the needle thread to pull off a length thereof and to shed said length automatically as the needle bar rotates.

7. In a buttonhole sewing machine, the

is. 1,1e

combination with a needle bar, of means to rotate it, a tension device for t ie needle thread, and a self-shedding pull-cit device carried by the needle bar and constructed to act on the thread to pull a length thereof through the tension device and to shed said length automatically as the needle bar rotates 8. In a buttonhole sewing machine, the combination with upper thread mechanism including a needle bar, means to rotate said bar in one direction to efifect stitching around the ends of a buttonhole and in the reverse direction between stitching operations, and a self-shedding pull-oil device carried by the needle bar and constructed to act on the upper thread during the reverse turning movement of the needle bar to pull off a length of upper'thread and then to shed said length automatically.

9. In a buttonhole sewing machine, the combination with a needle bar, of means to rotate it, and a pull-oi? device carried by tl e needle bar and presenting a self-shedding thread-engaging member having provision to engage the needle thread and pull oll av length thereof and then to shed said pulled-0E length as the needle bar turns.

10. in a buttonhole sewing machine, the

combination with a needle bar, of means to rotate it, and a pull-oil device carried thereby and presenting a curved thread engaging flange adapted to engage the needle thread and draw oil a length from the source of supply during the rotation of the needle bar in one direction only.

' 11. In a buttonhole sewing machine the combination with a needle bar, of means to rotate it, and a pull-oil device carried thereby and presenting a curved thread-engaging flange adapted to engage the needle thread as the needle bar rotates and draw otf a length from the source of supply, said flange being constructed to shed the drawn-oil length automatically as the needle bar rotates.

12. In. a buttonhole sewing-machine, the

combination with a needle bar, oi means to rotate it, a pulloil' device carried by the needle bar and presenting an apertured disk through which. the thread extends, and a curved thread-engaging flange having a thread-receiving.notch in one end adapted to engage the thread and draw off a supply thereof as the needlebar turns.

13. Ina buttonhole sewing machine, the combination with a needle bar, of means to rotate lt,l pull-oil device carried by the needle bar and presenting an apertu'red disk through which. the thread extends, and a curved threadengaging flange having a thread-receiving notch in one end adapted to engage the thread and draw 05 a supply thereof as the needle bar turns, said flange having a self-shedding bevel portion by which the drawn-oil length. of thread is antomatically shed during turning movement.

In testimonywhereof, I have signed my name to this specificatiom in the presence of two subscribing witnesses.

FRANK ZALESKI.

- Witnesses:

' F. A. SHEA,

Louis C. SMITH. 

